[Asterisk-Users] replacing step-by-step giving echo

[stoffell]

hi there,

We just encountered the following.. a customer has a tradifional PBX
that runs next to asterisk. Both PBX's have their own E1 line. Now
'some' numbers are forwarded from the traditional PBX to the new
asterisk server. (both have different DID numbers assigned)

When those numbers are called, basically the call arrives on the
traditional PBX, gets forwarded to the new number, meaning it goes out
the same E1 again, to the new E1 (different telecom operators).

Those calls are encountering echo most of the time. When dialing into
the E1 on the asterisk server directly, all goes well. (no echo)

Should I look into asterisk, the traditional PBX, or even the telecom operator?

cheers..